math7B_2010 - 3.3 Exploring Patterns 0910

Show your work/thinking and include at least one uploaded diagram or image.

April 18, 2010 Naasik Syed Math 7B

Big Idea: Negative Numbers Help Us To Model Many Real World Situations
Essential Question#3: How Do I Find the Difference Between Integers?

Problem 3.3 Exploring Patterns

15-5=10
15-4=11
15-3=12
15-2=13
15-1=14
15-0=15

Question A: Describe any patterns you observe in the way the differences change as the integers subtracted from 15 get smaller

Answer: As the integers subtracted from 15 get smaller, the difference gets bigger.

Question B: Use the patterns you observed to predict the answer to 15- -1

Answer: 16.

Chip Board 1Chip Board 2.jpg.doc

Click on this file to see the chip board.

Question C: Predict the answer to 15 - -4. Explain your reasoning

Answer: 15- -1= 15+1 Therefore 15- -4= 15+4.

Follow Up

1. Study the equations below
-10- 5=5
-10- 4=6
-10- 3=7
-10- 2=8
-10- 1=9
-10- 0=10

A. Describe any patterns in the way the defferences change as the integers subtracted from -10 get smaller

Ans. : The defference gets bigger

B. Use the patterns you observed to predict the answer to predict the answer to -10- -1

Ans. : -9

C. Predict the answer to 15- -4

Ans. 19 15- -1= 15+1 Therefore 15- -4= 15+4=19

2. When you add two negative integers, you get a negative sum. When you subtract two negative integers, do you get a negative difference? Explain

Ans. : No, if the negative integer on the right has a higher absolute value than the one on the right, the difference is positive